As a conventional technique for camera shake correction or image stabilization in photographing a digital image, two uniaxial angular velocity sensors are incorporated in a product such as a digital camera so as to detect a biaxial angular velocity. When the uniaxial angular velocity sensors are incorporated, it is necessary to ensure a region for incorporating the two sensors, thereby causing a problem with downsizing the product difficult.
A biaxial angular velocity sensor disclosed in Japanese Patent No. 3,492,010 (JP3492010) uses cross-shaped oscillator having first and second arm portions extending along an X axis from a fixedly supported central portion in mutually opposite directions and third and fourth arm portions extending along a Y-axis orthogonal to the X axis from the fixedly supported central portion in mutually opposite directions. The oscillator is formed in such a way that an electromechanical energy converting element is overlaid each on the first to fourth arm portions. Further, a plurality of drive electrodes for applying a voltage to the electromechanical energy converting elements are disposed on the oscillator so as to oscillate the oscillator in such a way that the first to fourth arm portions are displaced in a Z-axis direction orthogonal to the X and Y axes. Further, a plurality of detection electrodes are disposed on the first to fourth arm portions of the oscillator. The detection electrodes detect, from the electromechanical energy converting elements, voltages corresponding to displacements of the first to fourth arm portions due to respective angular velocities of the first to fourth arm portions around the X and Y axes while the oscillator is being excited. In the biaxial angular velocity sensor having the above configuration, when a voltage is applied to the drive electrodes disposed on the first to fourth arm portions, the respective arms of the oscillator are oscillated in the Z-axis direction. In this state, when the oscillator is moved in the X and Y axes directions or acceleration is generated, the respective arms are rotated, namely, angular velocities are generated around the X and Y axes by means of the Coriolis force. The angular velocities thus generated are detected from the outputs of the detection electrodes disposed on the arm portions. Then, the accelerations of the oscillator in the X and Y axes directions are measured from the detected angular velocities. In the above biaxial angular velocity sensor, the first to fourth arm portions are integrally formed, which helps downsizing of a product.